Air conditioner



FIG. 1 is a top, front, and right side perspective view of our design for an air conditioner;

FIG. 2 is a front view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a back side view thereof; and,

FIG. 7 is a bottom view thereof. 

We claim the ornamental design for an air conditioner, as shown. 